What is the smallest dog breed by height?

The Chihuahua is the smallest dog breed by height. It is a Mexican toy breed recognized for its compact body, large upright ears, and rounded “apple” skull. Adult Chihuahuas commonly stand about 15–23 centimetres (6–9 inches) tall, although individual dogs vary and breed standards often emphasize weight and proportions rather than a fixed height.

The breed’s ancestry is linked partly to pre-Columbian dogs of Mexico. Genetic studies suggest that modern Chihuahuas retain some of this Indigenous American dog ancestry, while the breed became formally established and internationally recognized in the early twentieth century. The American Kennel Club registered its first Chihuahua in 1904.

A common mix-up is confusing the smallest breed with the smallest individual dog. Chihuahua dogs have held the Guinness record repeatedly: Miracle Milly measured 9.65 centimetres at the shoulder, and Pearl, another Chihuahua, later became a record holder. “Teacup Chihuahua” is not a separate recognized breed; it is a marketing term for unusually small dogs, often associated with health risks.